Electric heater



- PatentedJune 6, 1922.

2 SHEETS-SHEET1.

gnvcwfoz Will/L's. W Hal/6 W. W. HALE.

ELECTRIC HEATER.

APPLICATION FILED JAN. 31, 1920.

RENEWED MAY 6, 1921- Patented June 6, 1922.

2 SHEETS-SHEET 2.

mni a glu-ucnfoa; TA7l'liZi5 W Zia/Le UNITED STATES WILLIS w. HALE, or CLEVELAND, OHIO. j

ELECTRIC HEATER.

Specification of Letters Patent. Patented J 11119 6, 1922.

Application filed January 31,1920, Serial No. 355,372. Renewed May 6, 1921. Serial'No. 487,320L

T 0 all whom it may concern:

Be it known that I, WILLIS W. HALE, a citizen of the United States, residing at Cleveland, in the county of Cuyahogaand State of Ohio. have invented certain new and useful Improvements in Electric Heaters, of which the following is a specification. I a

The present invention relates to an electric heater, and has for its object to provide a device of that character which embodies novel features of construction whereby a large surface heating area is provided and which also provides for a free circulation of air around the heating surfaces, thereby enabling great efficiency to be obtained.

Furtheriobjects of the invention are to provide an electric heater which is formed reference is to be had to the following de- 1 which heater constructe scription and accompanying drawings, in

Figure 1 is a tap plan view of an electric in accordance with the invention, one end of the. heater being shown in horizontal sectionand the supporting legs of the heater being broken away.

Figure 2 is aside elevation of the heater, portions being broken away and shown in section. V

Figure3 is a transverse sectional view on the line 33 .of Figure 1. r

Figure 4 is a plain view ofthe resistance element and one of the insulating thicknesses, showing the-same before they have been fitted between the reversely folded sheet metal thicknesses. I

a Figure 5 is an enlarged horizontal sectional view through a few of the reversely folded sheet metal thicknesses between which. the insulated resistance wire is positioned.

Corresponding and like parts are referred to in-the following description and indicated in all of the views ofthe drawings by the formation so that air can circulate through.

the same. By reference to Figure 1, it will be observed that each of the plates is formed with a channel shaped rib 3 which is reversely curved back and forth throughout the length of the plate, thereby providing a series of alternately disposed and oppositely opening loopsfc which are substantially in the shape of horse shoes. At the ends of the plates the channel shaped rib 3 is curved to provide closed loops 6, the extremities of the channel shaped rib intersecting the curved portions of the adjacent open or horse shoe shaped loops a. The ribs 3 have .both the upper and lower faces thereof channeled, so i that the upper and lower plates 1 and 2 are interchangeable, andthe looped portions a and b of the channel shaped rib are connected by suitable stiffening webs 4, while the peripheral portions of the plates are constituted by frames 5 of which the edge portions are shown as curved downwardly.

Interposed between the upper and lower plates 1 and 2 are the reversely disposed rolls of. the sheet metal thicknesses 6 between which the resistance element 7 is positioned. Each of the sheet metal thicknesses 6 has a lining 8 of insulating material so that the resistance element 7 which zigzags back and forth is properlyinsulated and kept out of contact with the sheet metal.

The two sheet metal plates 6 with-the insulating layers 8 and resistance wires 7 fitted between the "same are bent back and forth to provide the reversely disposed rolls 0 which correspond to the reversely disposed loops at of the channel shaped ribs 3 of the upper and lower plates '1 and '2. The edge portionsof these sheet metal thicknesses 6 are received within the channel shaped ribs 3 of the plates 1 and 2, and the parts are held rigidly in an assembled position by means of tie bolts 5) which connect the plates 1 and 2 and extend through certain of the open rolls 0 of the thicknesses 6. The end portions of these thicknesses 6 are bent to provide closed rolls which correspond to the closed end loops Z) of the channels 3, and the extremities of the sheet metal thicknesses are thus brought into engagement with adjacent rolls 3 so that the insulating material and resistance element are housed and protected at these points.

The lower plate 2 is provided at the corners thereof with legs 10 by means of which the heater as a unit may be supported in an elevated position. These legs may be of any conventional construction, being shown as secured at their upper ends to the frame 5 of the lower plate 2 by fastening bolts 11.

The resistance element 7 is preferably in the form of a crimped wire, as shown, which has a suitable composition so that it will be heated to the proper temperature when an electric current of the proper voltage is permitted to pass through the same. The two extremities of the resistance element are secured to binding posts 12 which are fitted into notches 20 in an extension 13 of one of the 'end stiffening webs L of the lower plate 2. Electric current is supplied to the heater through a conventional flexible cable 14 which passes through an insulating sleeve 15 in one end of the lower plate 2 and has the terminals thereof secured to the binding posts 12 and thereby placed in electrical connection with the resistance wires 7. These binding posts 12 are housed within one of the closed end rolls of the upright thicknesses so that they are effectively shielded and protected against coming into contact with any exterior object.

When the heater is in operation the resistance wires 7 will be heated by the passage of the electric current through the same. The heat from the resistance wires will be transmitted to the sheet metal thicknesses 6, and owing to the reversely rolled formation' of these thicknesses a large heating surface or area is provided. Not only is there a large surface provided for the radiation of heat, but the skeleton construction of the upper and lower plates and the open spaces between the'upright rolls provide in an effective manner for convection air currents. A very efiicient heater is thus provided, and it will be obvious that the peculiar construction enables the parts to be assembled without difficulty and without the necessity of providing a large number of fastening members. The insulating layers 8 and remstance wir s 7 are positioned between the two sheet metal thicknesses 6 while the latter are in a Hat condition, after which the assembled thicknesses with the resistance ele- Inent between the same are reversely bent to provide the rolls (1. The upper and lower edge portions of the rolls are received within the channels 3 of the upper and lower plates so that all of the parts are held rigidly in proper position by means of the tie bolts 9.

The asbestos layers or thicknesses 8 are preferably treated with some suitable chemical substance such as a solution of silicate of soda or water glass for the purpose of causing them to become good conductors of heat without destroying their insulating properties for electricity.

While I have illustrated and described one particular embodiment of the invention, it will be obvious that many changes and modifications can be made in the details of construction without departing from the fundamental and underlying idea of the invention.

Having thus described my invention what I claim as new is 1. A heater including opposed plates having corresponding channels therein, sheets having edge portions thereof received within the channels, means connecting the opposed plates to hold the parts in an as sembled relation, and heating means between the sheets.

2. A heater including opposed plates provided with channel shaped ribs having corresponding configurations, sheets interposed between the plates with edge portions thereof received within the channel ribs, tie means connecting the plates, and heating meansbetween the sheets.

3. A heater including opposed plates pr0- vided with channel shaped ribs which extend back and forth in similar configurations on the two plates, sheets extending edgewise between the plates and bent back and forth so that edge portions thereof are received within the channels, tie means connecting the plates, and an insulated resistance member between the sheets.

4. A heater including opposed plates provided with channel shaped ribs which extend back and forth across the plates to provide corresponding intermediate loops and have the extremities thereof returned to provide closed end loops, sheets extending between the opposed plates and having the intermediate portions thereof bent back and forth while the end portions are looped so that edge portions of the sheets are received within the channel shaped ribs, and an insulated resistance element arranged between the sheets.

5. A heater including similar and interchangeable opposed plates, provided with ribs having channels on opposite sides there of and arranged in corresponding configuraing the plates, and an insulated element between the sheets.

6. A heater including upper and lower skeleton plates arranged in anopposed relation, sheets extending between the plates and bent to provide a plurality of rolls, tie means connecting the plates for clamping the sheets between the same, and a resistance element between the sheets.

7. An electric heater including a pair of metal sheets, a resistance confined between the sheets, and means having a detachable interlocking engagement with-the. edges of i the sheets to holdthe parts in assembled relation.

8. An electric heater including a pair of metal sheets, a resistance confined between the sheets, and plates engaging edge portions of the sheets and interlocking therewith to hold the parts in assembled relation.

9. An electric heater including a pair of metal sheets, a resistance confined between the sheets, and plates having channeled portions which receive edges of the sheets to hold the parts in assemble-d relation.

10. An electric heater including a pair of metal sheets, a resistance confined between the sheets, said sheets having end portions thereof returned to protect the exposed edges of the sheets at the ends thereof, and opposed plates engaging the remaining edges of the sheets to protect the same and hold the parts in assembled relation.

11. An electric heater including a pair of metal sheets, a resistance confined between the sheets, said sheets having the ends thereof returned to protect the exposed end edges of the sheets, and opposed plates having channeled portions receiving the remaining edge portions of the sheets to protect the same and hold the parts in an assembled re-' 'opposed'metal sheets, a. sheet of-insulating material applied to the inner face of each metal sheet, and a resistance element-closely confined between the metal sheets, said re-' sistance element being directly engaged by the insulating sheets and held in position thereby. a

14. An electric heater including a pair of opposed metal sheets, a sheet of insulating material applied to the inner face of each of the metal sheets, and a resistance wire zigzagged back and forth between the metal sheets and closely confined between the same, said resistance wire vbein in direct engage ment with the sheets'of insulating material and being held in proper position thereby.

15. An electric heater including a pair of opposed. metal sheets which are reversely bent back and forth to provide oppositely opening loops extending transversely thereof, a sheet of insulating material applied to the inner face of each of the sheets, a resistance element closely confined between the metal sheets and directly engaged by the insulating sheets, and means engaging the metal sheets to hold the parts inan assembled relation.

16. An electric heater including a pair of opposed rectangular metal sheets which are reversely bent back and forth to provide oppositely opening loops extending transversely thereof, sheets of insulating material applied to the inner faces of the metal sheets,

a resistance wire zig-zagged back and forth.

in an opposed relation, sheets extending between the plates and engaged thereby to hold them in operative position, and a resistance element confined between the sheets. 18. An electric heater-including upper and lower plates arranged in an opposed relation, sheets having edge portions thereof in engagement with the lates and bent to provide a plurality of rol s, and a resistance element closely confined between the sheets.

19. An electric heater including a pair of opposedslieets arranged in a substantially upright position, an insulated resistance element closely confined between the sheets, and upper and lower transversely disposed skeleton plates associated with the upright sheets, the skeleton formation of the plates facilitating the movement of convection currents at the sides of the sheets.

20. An electric heater including a pair of substantially upright sheets, an insulated resistance element closely confined between the upright sheets, said sheets having substantially vertical bends therein which provide upright air channels, and upper and lower transversely disposed skeleton plates associated with the sheets, and the skeleton forversely disposed plates associated with the sheets. one of the plates having a skeleton formation and the openings therein registering with the upright channels of the sheets to facilitate the movement of convection air currents.

In testimony whereof I aflix my signature.

WILLIS W. HALE. 

